Textile products made from needling a fibrous web



R. D. WELLS Sept. 11, 1962 TEXTILE PRODUCTS MADE FROM NEEDLING A FIBROUSWEB Original Filed June 13, 1958 2 Sheets-Sheet 1 INVENTOR RICHARD o.WELLS @h/fiv T ATTORN Zf Sept. 11, 1962 R. D. WELLS 3,052,948

TEXTILE PRODUCTS MADE FROM NEEDLING A FIBROUS WEB Original Filed June13, 1958 2 Sheets-Sheet 2 FIG.|2 S41 FIG.I4

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utmmm m? \NVENTOR RICHARD D. WELLS ATTORNEY ilnited States hatent @fiice3,@52,943 Patented Sept. ill, 1962 7 Claims. c1. 28-79) This applicationis a division of my copending application Serial No. 741,859 filed June13, 1958, which application relates to a method and apparatus forneedling a fibrous web. This divisional application relates particularlyto a textile product or structure made by needling a fibrous web or battof loosely assembled fibers, said product being shown but not claimed inthe above-identified original application.

In the making of so-called nonwoven fabrics there is ordinarily employedsome form of adhesive to hold the fibers together, or when thermoplasticfibers are used, they are stuck to each other by a heating process. Suchfabrics, however, do not have the same feel or texture commonly found inknit and woven fabrics. In order to attain a more acceptable feel, it isan important object of the invention to eliminate the use ofobjectionable amounts of adhesive or thermoplastic fibers by making anonwoven fabric wherein there is a mechanical interlocking or bonding offibers.

The usual batt or web of fibers ordinarily does not have sufficientstrength to withstand the strains of ordinary usage and it is a furtherobject of the invention to gather certain of the fibers into reenforcingyarn-like structures which act to strengthen and reenforce the web orbatt.

By way of illustrating the invention, five types of structure are setforth in one of which the reenforcing zones or structures are transverseof the plane of the web and extend from at least one surface of the webinto the latter in such manner as to gather or twist fibers inconcentrations which are connected to each other by fibers which partakeonly partly of the twisted concentrations. In the second form of theinvention reenforcing yarn-like structures are formed lengthwise in asingle batt or web of fibers, and in the third form two batts or websare brought into tangential or at least surface contact with each otherand the reenforcing structures are made from fibers drawn from bothwebs. In the fourth form reenforcing structures are formed on both sidesof a web. in the fifth form the fibers are gathered together to form ayarn-like structure which is not necessarily connected to any similarstructure but can be used either as a step for further treatment toproduce yarns or can be used directly as produced as will be set forthhereinafter.

In order to produce the reenforcing yarn-like struc tures it is animportant object of the invention to subject the fibers in localizedzones of the web to rotary action which will coil at least some of thefibers on themselves and wherein some of the coiled fibers extend intoadjacent areas of the web to have frictional contact with other fibersnot necessarily entangled in the yarn structure.

It is a further object of the invention to use fibers some of which willhave a length sufiicient to extend from one reenforcing structure to anadjacent similar structure and become coiled into both structures sothat the lateral strength of the web is increased. A still furtherobject of the invention is to make a continuous yarn-like structure froma web or batt which has been split into a number of separate tapes orribbons from each of which the fibers are collected in a manner to formindivdual yarnlike structures.

Many nonwoven fabrics lack the property of drape and are also onlyslightly elastic in any direction, particularly lengthwise andcrosswise. It is an important object of the present invention to make aproduct in the nature of a nonwoven fabric which is capable of elasticstretch lengthwise and also crosswise.

This latter characteristic of the fabric is attained by coilng some ofthe fibers helically so that the yarn-like structure has lengthwiseelasticity and spirally coiling other fibers, or parts of those coiledhelically, to permit uncoiling to provide transverse elasticity.

In the accompanying drawings wherein examples are given of each of thefive types of structures already mentioned,

FIG. 1 is a diagrammatic combined plan and side View of a fabric madeaccording to the first form of the invention wherein short reenforcingstructures are assembled out of fibers in the web and extend at leastpartway through the web from one side to the other,

FIG. 2 is a diagrammatic View similar to KG. 1 but wherein lengthwiseyarn-like structures have been formed in a single web of fibers,

FIG. 3 is a diagrammatic view similar to FIG. 2 but wherein the web hasbeen made by joining two distinct Webs by reenforcing yarn-likestructures located between the two Webs and having their fibers drawnfrom each of the webs so that the latter are closely bonded to eachother,

FIG. 4 is a diagrammatic view showing an end of a fabric similar to thatshown in FIG. 2 but with a row of reenforcing yarn-like structure onboth sides thereof,

FIG. 5 is a diagrammatic View showing a single yarnlike structure formedas such without reference to a fabric,

FIG. 6 is an enlarged diagrammatic section on line 66, FIG. 2,

FIG. 7 is a diagrammatic view looking in the direction of arrow 7, FIG.6, illustrating the manner in which a single fiber can be joined to twoadjacent yarn-like structures,

FIG. 8 is an enlarged diagrammatic section on line 88, FIG. 3, showingthe manner in which two webs can be joined as contemplated in the thirdform,

FIG. 9 is a view similar to FIG. 6 but showing a modified form of fiberrelationship,

FIG. 10 is similar to FIG. 8 showing a variation thereof,

FIG. 11 diagrammatically shows a fabric such for instance as set forthin FIG. 2 in normal size in full lines and in stretched size in dottedlines,

FIGS. 12 to 15 diagrammatically show fabrics of different forms but allof the general type shown in FIG. 4,

FIG. 16 is a diagrammatic plan view of a fabric made according to theinvention showing various fiber relations,

FIG. 17 is a side elevation in diagrammatic form showing a machine forproducing the type of fabric shown in FIG. 1,

FIG. 18 is a diagrammatic elevation of a machine looking in thedirection of the feed of the web to be acted on for producing, forinstance, the types of fabrics shown in FIGS. 2, 3 or 4,

FIG. 19 is a diagrammatic side view looking in the direction of arrow19, FIG. 18,

FIG. 20 is a diagrammatic view showing part of the structure shown inFIG. 19 in a somewhat different position for producing, for instance,the type of fabric shown more specifically in FIG. 2,

FIG. 21 is a diagrammatic View showing structure and method forproducing the fabric shown in FIG. 4,

FIG. 22 is a diagrammatic plan view showing a variation in the structureshown in FIGS. 18 and 19 whereby the needles turn in the same direction,and

. jecting the web to some restraint.

FIG. 23 is a diagrammatic plan view looking in the direction of arrow23, FIG. 19, parts being omitted, showing the web split into a number ofseparate tapes or ribbons for forming the. single structure hown in FIG.5.

Referring more particularly to FIG. 17 which diagrammatically shows amachine to produce the type of fabric illustrated in FIG. 1, frame hasupright posts 11 which support a table 12 having a bearing 13 slidableon each post 11. Extending over and secured in fixed position on thetable 12 is a Web supporting plate 14 provided with perforations 15 toregister with other perforations 16 in a second plate 17 mounted overthe plate 14. The plate 17 is mounted for rising and falling motion andhas end supports 13 which normally rest on fixed stops 19 which limitdown motion of plate 17.

The machine has a shaft 20 driven in any convenient manner to which issecured a crank 21 connected by links 22 to feed arms 23 rockable aboutfixed studs 24. Each arm 23 has a feed pawl 25 which meshes with aratchet wheel 26 rotatable on the corresponding stud 24 and secured to apulley 27. Each pulley drives a belt 28, the belt at the left driving afeed pulley 29 for a flexible web feeding belt 30 trained around anidler pulley 31. The belt 28 at the right drives a pulley 32 for aflexible takeoff belt 33 trained around an idler pulley 34. A takeofiboard 35 receives material fed to it by belt 33. Hold pawls 36 preventretrograde motion of ratchet wheels 26.

A cam 40 is secured to shaft 20 and has a low dwell 41, an incline 42, ahigh point 43 and a decline 44. The cam engages a roll 45 rotatablymounted on the underside of table 12. Rotatable needles are normallylocated above plate 17 in register with the openings 16 in the top plateand 15 in the bottom plate. Each needle N at the lower end thereof has aslightly offset barb B for engagement with the fibers of a web or battW1.

In the operation of the machine shown in FIG. 17 the web or batt W,which is made of a large number of loosely assembled fibers, is fed bybelt 30 to the space between plates 14 and 17' when the low area 41 ofcam 40 has let the roll 45 and table 12 down to their low positions. Atthis time the crank arm 21 will be giving feeding strokes to pawls 25 toadvance belts 30 and 33 to feed the web between the plates 14 and 17..When the crank arm has made a half turn and starts a reverse motion ofthe feed pawls 25 the cam 40 will lift the table 12 and plate 14 toelevate the web against the plate 17 and lift it off the supportingstops 19, thereby sub- As the cam continues to turn the plates 14 and 17and also the web rise so that the needles N can pass through the holes16 and rotate in the web to gather fibers into coiled form at spacedintervals as shown for instance at S1, FIG. 1. The holes 15 are providedin plate 14 to permit the needles to go entirely through the web if thisis desired. As the crank 21 continues the idle motion of the pawls thecam 40 continues to turn and lower the plate 14. The plate 17, by itsweight, will move the web down away from the needles and come to rest onthe stops 19. This will complete the operation with respect to a sectionof the web and the belt 33 will then move the treated web onto thetake-off table or board 35 as the belt 30 feeds the next section of webbetween plates 14 and 17. In this way the web is provided withtransverse reenforcing areas of coiled fibers some at least of whichextend into adjacent parts of the nontreated web to have frictionalholding contact therewith.

The needles may be mounted and operated as shown for instance in FIGS.18 and 19. In FIG. 18 the driving motor M has a drive pulley 46connected by belt 47 to driven pulley 48' secured to the upper end of avertical shaft 49. The shaft 49 extends down through a top plate 50 andhas secured thereto a gear 51 and continues beyond the latter and hasmounted on the lower end thereof a chuck 52 in which the upper end orshank of a needle 4 N is secured. Other chucks 53 similar to chuck 52are mounted on vertical shafts 54 each having a gear 55 secured thereto.The gears 51 and 55 mesh, adjacent gears and needles turning in oppositedirection. The vertical position of the chucks. is determined by asecond plate 56 vertically adjustable by nuts '57 on upright screws 58the lower ends of which are secured to the frame 59.

As the motor M turns it causes rotation of shaft 49 which in turn causesrotation of all of the needles and this arrangement can, if desired, beutilized to drive the needles N which are shown in FIG. 17. The lowerend of each needle is provided with the barb B offset slightly from theshank of the needle and it is the barb on each needle which gatherscertain of the fibers into the yarnlike structures S1 of FIG. 1. Theshafts 49 and 54 have collets 6% which engage the under side of plate 56to limit upward motion of the chucks and needles. The gears which aresecured to the shafts rest on collars or washers 61 supported by the topof plate 56. In this way vertical adjustment of the plate '56 determinesthe positions of the lower ends of the needles.

When making the fabric shown in FIG. 2 from a single web of fibers theweb W2 is fed onto a drum 65 see FIG. 20, which can be turned by meansof gear reducer 66 shown in FIG. 18 as being driven by a connectingshaft 67 turned by the motor M. The needles shown in FIG. 20 have beendisposed to operate at an angle but in other respects the drivingmechanism will be as already described in connection with FIGS. 18 and19. Theweb W2 is fed in the direction of arrow a, FIG. 20, and the freeends of the needles terminate close to the friction, soft rubber,surface 68 of the drum or cylinder 65. The ends of the needles have thebarbs on them extended into the Web and rotate at a speed sufiicient togather fibers into yarn-like assemblages or coils S2 which runlengthwise of the web, these yarn-like structures being to the left ofthe needle as viewed in FIG. 20.

When producing the fabric shown in FIG. 3 the needles can have thedisposition shown in FIGS. 18 and 19, that is, upright with their barbedlower ends terminating near the nip between two cylinders 70 and 71which turn in opposite directions as indicated by arrows b and 0, FIG.19. These are the drums which are shown in FIGS. 18 and 19 and aredriven by the gear reducer 66 so that their angular speed isconsiderably less than the rotational speed of the needles. Two webs W3Aand W3B are trained respectively over the upper parts of the cylinders70 and 71 which may be similar to the drum or cylinder 65. As the drums70 and 71 turn they draw the webs down to the space or nip between themand cause the two webs to come into surface engagement with each otherat a point approximately at the lower end of the needles. As the needlesturn their barbs collect fibers from each of the two webs W3A and W313into yam-like structure S3 and in this way unite the two webs into asingle web W3 which corresponds to the web shown in FIG. 3. The lowerpart of FIG. 3 shows the web WSA as at the top and the web W3B as at thebottom with the yarn-like structures S3 connecting these two webs toform the single united web W3. As shown in FIG. 19 the fabric W3 is leddown around guide rolls and then to a wind-up roll 74 which can bedriven from the reducer 66 somewhat after the manner of driving clothrolls in looms. A similar wind-up drum or roll can be provided tocollect each of the various products set forth herein.

Experience shows that the barbs B can occupy several different positionswith respect to the broken line L showing the centers of the twocylinders 70 and 71, that is, they can be slightly above the line, onit, or slightly below it. Whatever their position it is desirable thatthe two webs be under some compression and that the barbs turn on axeswhich lie on the plane of contact of adjacent surfaces of the two websW3-A and W3B. The single web shown in FIG. 2 can be passed between thetwo rolls 70 and 71 if desired, and it need not necessarily be made asindicated in FIG. 20.

FIG. 21 illustrates diagrammatically the structure by which the fabricshown in FIG. 4 is produced. In FIG. 21 a roll 90 feeds a web W4 to thefirst set of needles 91 which produces yarn-like structures S41 on oneside of the web W4. The latter then moves to a second roll 92 and asecond set of needles 93 produces yarn-like structures S42 on theopposite side of the web. The latter is then led over a roll 94 to awind-up mechanism (not shown) similar to that shown in FIG. 19.

FIG. 22 shows how the needles of a bank can all be rotated in the samedirection. Plate 95 similar to plate 56 replaces the latter and hasrotatable thereon pinions 96 which mesh with gears 97 smaller indiameter than gears 51 and 55. A central vertical shaft 98 is similar toshaft 49 and other shafts 99 are similar to shafts 54-. In this way allthe needles turn in the same direction as distinguished from the formshown in FIGS. 18 and 19 wherein adjacent needles turn in oppositedirections.

By turning the needles in the same direction, all the fibers of a webare coiled in one direction as opposed to fibers coiled in oppositedirections with respect to each other when the mechanism of FIG. 18 isemployed as set forth hereinafter.

The single yarn-like structures such as shown in FIG. 5 can be producedas set forth in FIG. 23 wherein the web, before reaching the feed roll100, has been split into thin tapes or ribbons 101. A needle 102 isprovided for each tape and may be mounted and operated as alreadydescribed. As roll 100 and the needles 102 turn the fibers of the tapeswill be gathered into coiled forms 55, but unlike the previouslydescribed forms, the yarn-like structures in this instance are separateand do not form parts of a fabric.

The different mechanisms briefly described hereinbefore form no part ofthe present invention and are fully described and set forth in mycopending application cited above.

When making the nonwoven fabrics set forth herein, the fibers in the webmay be disposed in various ways and, because of this, the manner inwhich the barbs on the needles engage the fibers will vary and thereforehave more effect on some fibers thans others. If the fibers are of apreferred random distribution in the web some of them will approach aneedle parallel to the direction of feed of the web and be littleaffected by the needle. Other fibers may be disposed crosswise of theweb feed and will be engaged either near an end or at a point more orless midway of the ends. Still other fibers will be oblique to thedirection of travel and may have one end engaged by one needle and laterhave the other end engaged by an adjacent needle. Other fibers may notbe directly engaged by any needle but will be frictionally touching afiber that is acted on by a needle and to some extent have its positionchanged by the first fiber. Other fibers may be transversely disposedbut not be afiected by a needle. No attempt is made herein to show allpossible arrangements and dispositions which the fibers can occupy asthey move toward the needles as the Web is drawn forwardly. A fewspecific fiber relations will be described but they are not by any meansto be considered as anything more than representative examples.

The fibers are acted on by two forces one of which moves the web in anonward or forward direction and the other of which arises from therotating needles and produces the coiling of the fibers. The onward feedtends to draw the coils into lengthwise helical form and the needlestend to arrange parts at least of the fibers into spiral form. Many ofthe fibers are therefore both helically and spirally coiled and can bestretched lengthwise due to the helical coiling and can be partlyuncoiled when the fabric is stretched crosswise due to the spiralcoiling. Some uncoiling can occur in the helically wound parts of thefibers incident to crosswise stretch.

In FIG. 6 a single fiber 111 is shown as connected to two adjacentstructures S2 between which a straight part 111 of the fiber extends.The left-hand end of fiber has been coiled in a counterclockwisedirection and the right-hand end in a clockwise direction by reason ofthe opposite direction of rotation of the needles with reference to FIG.18. FIG. 7 shows one possible arrangement of the helically coiled parts112 and 113 of the fiber 110.

FIG. 8 shows a fiber 115 disposed similarly to fiber 119 except that itsstructures S3 are common to the two Webs WA and WB which they join. FIG.6 shows two fibers 118 and 119 caught into the right and left-handstructures S2 respectively and extending into adjacent parts of thefabric, or to adjacent similar structures (not shown). Similarly, fibers120 and 121 extend to the right and left from structures S3 in FIG. 8.

FIG. 9 is a view similar to FIG. 6 except that the yarn-like structuresare produced by needles all of which turn in the same direction, seeFIG. 22, and FIG. 10 is similar to FIG. 8 but with the same exception.The fiber 125 in FIG. 9 passes from the top of one of the coiledstructures down through the web to the bottom of the adjacent structure,this being true also in FIG. 10. In FIG. 9 fibers 126 are similar tofibers 118 and 119, FIG. 6, and in FIG. 10 two fibers 127 and 128, onefrom the upper web WA and the other from the lower web WE are shownconnected to the lefthand yarn structure S3.

FIG. 11 illustrates digramrnatically a valuable prop erty possessed bythe fabrics already described. Taking the second fabric as an example,and referring to FIGS. 6 and 7, the fabric W2 may have an originallength e but because of the helical coiling shown in FIG. 7 the lengthcan be stretched or increased to The original width g can be increasedto the width 11 due to uncoiling of the spirals shown in FIG. 6, or touncoiling of the helices. On release of the stretching forces thehelical and spiral coils will tend to return to their original forms.The fabric is thus seen to possess considerable elasticity due to thecoiling of the fibers. rms property is possessed by other of thefabrics, such as W3 and we.

In the fabric W1 the yarn-like structures S1 are short and transverse ofthe plane of the web, but these structures S1 are spirally and helicallycoiled and can un Wind in response to lengthwise and transversestretching forces.

When a single web is being made, as in FIG. 20, or when being fed by oneof the drums in FIG. 19, the yarnlike structure S2 is likely to benearer one side of the web than the other and it is for this reason thatthe diagrammatically illustrated mechanism in FIG. 21 can produce thefabric W4. FIGS. 12-15 show digrammatically some of the forms of fabricW4 with particular reference to the direction of rotation of the needlesshown in FIG. 21.

In FIG. 12 the direction of coiling for the top structures S41 isclockwise whereas for the lower structures S42 the direction iscounterclockwise. The structures S41 and S42 are staggered as shown sothat if the fabric is subjected to a later compressing operation thestructures of the two series can nest close to or between each other.

In FIG. 13 the top series S41 is made by needles operated as in FIG. 18whereas the bottom series is made by needles turning as for the bottomseries in FIG. 12.

In FIG. 14 both top and bottom series are coiled clockwise, while inFIG. 15 both series are formed by needles which rotate in oppositedirections for each series.

As already mentioned the fibers can assume a great many differentpositions and relations only a few of which will be described inconnection with FIG. 16. In that figure a fiber 131 is shown coiled intothe left-hand structure S2 and having a free end 131 which hasfrictional holding relation with the free end 132 of another fiber 133coiled into the central structure S2. Another fiber 134 coiled into theleft-hand structure has a free end 135 which has frictional holdingrelation with an uncoiled fiber 136 lying between two adjacentstructures but not directly connected to either of them. Other fibers137 are not connected directly to any structure 82, and fiber 138similar to fiber 110 is shown as frictionally engaged with another fiber139 not connected to any structure S2. Other of the fabrics can havesimilar fiber relations. 7

In FIG. 12 the series of structures S41 and S42 are shown as crossconnected by fibers 140 which, like others similar to them but notshown, tend to bind the two series together, the ends of fiber 140 beingcoiled into structures on opposite sides of the web. Similarly, fibers141, 142 and 143 in FIGS. l3, l4 and respectively bind the structuresS41 and S42 in each form to each other.

In the making of a fabric, a web containing viscose fibers and 75%acetate fibers was used. Tests were made of samples of the web one inchwide, six inches long, and about one-quarter inch thick. The testsshowed an average breaking strength of the unprocessed web samples of4.3 grams, whereas the processed samples containing a single lengthwiseyarn-like structure, as S2, had a breaking strength averaging 23.4grams. The coiling of the fibers therefore resulted in an increase ofmore than 500% in the strength of the web. Both the processed andunprocessed samples had in them approximately the same number of fibers.

The web from which the fabric is produced is not limited to the specifictypes of fibers mentioned and the fibers can be of different lengths andmay be either oriented, as lengthwise of the web, or placed at random.

The separate tape or ribbon webs shown in FIG. 23 can be cut orotherwise derived from a wider web in any approved manner. One methodcould, for instance, be similar to the procedure set forth in AmericanWool Handbook, 1948, published by Textile Book Publishers, Inc., NewYork city, the chapter on Blending and Woolen Carding, section on TapeCondensers.

The yarn-like structure shown in FIG. 5 can be pro duced by a needleoperating at approximately 400 rpm. while each of the tapes 101 is fedat about two feet per minute. Other speeds of needle rotation and tapeor web feed were found to be satisfactory and the smaller the offset ofthe point of the barb from the shank axis of the needle the smaller willbe the diameter of the yarnlike structure. The barbs B of course arehoned in order to insure clearance of the structures S1S5 from theneedles as the webs are advanced.

While reference has been made to the spiral arrangement of parts atleast of the coiled fibers, it is to be understood that the feature setforth in FIG. 11 for instance, especially the transverse stretching, canbe derived from the helically wound parts of the fibers as well as anyparts which may be spirally wound. Since the coil arrangement is madearound a needle having an appreciable diameter the coils at one point intheir formation may be hollow, but it is found that as the operationproceeds the yarn-like structures tighten on themselves. so that in thefinished product there is only a small axial hollow observable in thestructures.

In all forms of the invention there is a gathering of fibers or partsthereof from a web after which the fibers or parts thereof are subjectedto rotary action to orient them partly spirally and partly helically. Inthe form shown in FIG. 1 the coil structures are shown substantially atright angles to the plane of the web but they could, if desired, bedisposed at an angle by an appropriate modification of the machine shownin FIG. 17.

In other forms the web at the zone of operation is moving, more or lessparallel to the axis of the needles and for this reason the web can bemoved continuously instead of intermittently as contemplated in FIG. 17.The single web shown in FIG. 2 can be made either as suggested in FIG.20 or by the structure shown in FIG. 19 wherein only one web will be fedover one of the drums.

Although the form of product shown in FIG. 5 has been described as madefrom tapes or ribbons of fibers formed as such before reaching theneedles, it may also be made by moving a wide web to the needles andcutting it into tapes at the needles. In fact, cutting may be omittedand reliance placed on the needles to separate the structures S5 fromthe web.

In any of the coils shown in any of the forms described the fibers maybe set in the coiled configuration by means well known in textile artssuch as the heat-setting of thermoplastic fibers or chemical treatmentswhich produce memory effects, thus enhancing the elastic behavior of theweb system as set forth in FIG. 6.

Having now particularly described and ascertained the nature of theinvention and in what manner the same is to be made, what is claimed is:

1. A web of loosely assembled fibers certain of which are Wrapped aroundeach other spirally and helically to form groups to provide local areasof reenforcement extending lengthwise of the web and are alsofrictionally engaged with fibers of the web located between said localareas.

2. A web of loosely assembled fibers certain of which are wrapped aroundeach other spirally and helically to form groups to provide local areasof reenforcement and are also frictionally engaged with fibers of theweb located between said local areas, said web having top and bottomsurfaces and the groups extend lengthwise through the web between saidtop and bottom surfaces.

3. A nonwoven fabric formed of loosely assembled fibers havinglengthwise coiled groups of fibers spaced transversely of the fabric,certain at least of the coiled fibers extending from their respectivegroups into the fabric between groups and being helically disposed topermit stretching of the fabric in the direction of the length of thegroups and being spirally disposed to uncoil in response to stretchingof the fabric transversely of the groups.

e 4. A nonwoven fabric formed of loosely assembled fibers havinghelically and spirally arranged lengthwise groups of fibers spacedtransversely of the fabric, the fibers in the groups due to theirhelical arrangement expanding in response to.a stretching force appliedlengthwise of the groups to permit increase in length of the fabric anddue to their spiral arrangement uncoiling in response to a stretchingforce applied transverse of the groups to permit increase in the widthof the fabric.

5. The fabric set forth in claim 4 wherein certain of the fibers of eachgroup extend transversely and are connected to an adjacent group.

6. The fabric set forth in claim 4 wherein certain of the fibers of eachgroup extend away from the latter and have frictional engagement withfibers of the fabric between groups.

7. A nonwoven fabric having an elongated group of fibers arrangedhelically to stretch in response to a tension force applied to the grouplengthwise thereof and arranged spirally to uncoil in response to atension force applied to the fabric transverse of the group.

References Cited in the file of this patent UNITED STATES PATENTS

